Figure 1: Sample where file has not changed

1) fchange counts 2 lines in the log file

----r----- 1 bin mem 604136 Jul 21 1992 /unix
----rw---- 1 bin mem 605100 Aug 28 1992 /unix

2) a new line is added via ls.

----r----- 1 bin mem 604136 Jul 21 1992 /unix
----rw---- 1 bin mem 605100 Aug 28 1992 /unix
----rw---- 1 bin mem 605100 Aug 28 1992 /unix

3) the lines are sorted uniquely, causing one of the duplicate  lines to be removed.

----r----- 1 bin mem 604136 Jul 21 1992 /unix
----rw---- 1 bin mem 605100 Aug 28 1992 /unix

4) fchange counts again and sees that there are still two lines.

5) therefore the file hasn't changed.